Wheelchairs are well known transportation appliances enabling the infirm, disabled and unwell person to move about with greater mobility than otherwise. Essentially, wheelchairs are small, single person conveyances typified by a chair supported by two outer, large diameter drive wheels, and with two smaller pilot wheels or caster wheels located in front of the user's center of gravity. The chair may include a padded seat, or it may include a webbing or sling seat. Alternatively, the chair may be molded from a suitable material. A chair back is typically provided for the user's comfort. A leg rest assembly may be attached to the seat. Motive power may be supplied by an attendant pushing the wheelchair, by the user's hands and arms, or by an auxiliary power source.
While wheelchairs following many different designs have proliferated, there have been drawbacks heretofore that remain to be solved. In order to meet the needs and demands of the physically handicapped user, wheelchairs must be versatile and easily and readily adapted to accommodate the particular body shape and size of the user. Wheelchairs must also be versatile in adapting to both ambulatory and recreational travel, and they must be sufficiently rugged and durable to provide comfortable passage over uneven and irregular surfaces.
For instance, wheelchair design has not solved the need for shock and vibration dampening control to provide extended opportunities and mobility to the user.
A hitherto unsolved need has arisen for a lightweight adjustable wheelchair, wherein the chassis is made from materials which inherently provide vibration and shock dampening. Another unsolved need has been for a universal, adjustable chassis and wheel assembly. Yet another unsolved need has been to provide a more fully collapsible, modular wheelchair whereby the wheelchair may be easily disassembled and stowed in pieces in small spaces, such as in an overhead storage compartment of an airplane.
A further unsolved need has arisen for a chassis and wheel assembly permitting wheelchair adjustments within a plurality of dimensions and ranges. Still one more unsolved need has been for a modular wheelchair which may be customized to the needs of a particular patient by a therapist with simple adjustments without special skills, tools or training. In addition, an unsolved need has been for a more universal chassis and wheel assembly in which a variety of seating system designs may be readily used without impairment.